The present invention relates generally to refrigerated cabinets, more particularly to a mullion bar assembly having enhanced heat transfer barrier characteristics to reduce the energy consumption of the refrigerated cabinet.
Conventional refrigerators typically have insulated freezer and fresh food compartments which are disposed in either a side-by-side, or top mount configuration. In the construction of such a refrigerator cabinet, an insulated interior wall is utilized to separate the interior space of the cabinet into the freezer and the fresh food compartments. Integrally molded plastic liners may be used to line the respective compartments. An insulation material is typically disposed between the compartment liners and the metal outer shell of the refrigerator cabinet.
A mullion bar assembly may be affixed to the front face of the interior separating wall. The mullion bar assembly typically includes a metallic mullion bar which extends over a substantial area of the front face of the interior wall.
It is well known in the art to utilize magnetic gasket seals around the edges of the doors of the refrigerator cabinet. Since the mullion bar is typically made of a metallic material and is also exposed to the ambient atmosphere, it has proven very convenient to extend the width of the mullion bar to a substantial portion of the width of the front face of the interior wall and to allow the magnetic gaskets to seal against the mullion bar. However, to do so inevitably exposes at least a portion of the metallic mullion bar to the interior of either the freezer or the fresh food compartments. Since the mullion bar is a metallic material, such exposure provides a pathway for the heat transfer from the ambient atmosphere into either the freezer or the fresh food compartment. When such ambient atmosphere is humid, condensation will appear on the face of mullion bar. It is well known in the art to provide an electrical heater behind the mullion bar which, when turned on, raises the temperature of the mullion bar to eliminate this condensation. However, since a portion of the mullion bar is exposed to the freezer and the fresh food compartments, raising the temperature of the mullion bar inherently raises the temperatures in these compartments.
Due to the exposure of the mullion bar to the freezer and the fresh food compartments, the energy requirement for the mullion bar heater is also increased since, in order to remove the condensation, the heater must raise the temperature of the mullion bar (which has been cooled via exposure to the freezer and fresh food compartments) a substantial amount. Since the freezer compartment is typically maintained at a temperature of 0.degree. F. and the fresh food compartment is maintained at a temperature of approximately 38.degree. F., it is apparent that the undesirable heat transfer via the mullion bar imposes an additional load on the central refrigeration system, as well as the mullion bar heating system.